To be competitive, you need to update your old posts?

I can give you some reasons to do this.

1. First reason: It is fastest to correct a post than to write a new one.

2. Second reason: To provide a "good" quality of content, it means to provide updated information to your readers/customers.

3. Third reason: Add new photos or /and links to the article, which will give the article a new "look" or a fresh view.

4. SEO, Let see what are the professionals and Guru's saying about this issue:

4.1 Neil Patel https://neilpatel.com/blog/updating-old-content-to-boost-ranking/ said "is important because, in Google's algorithm, you're more likely to rank higher if more people click on your content from the search engine results page. So updating your content will make it more appealing, and that appeal will tell Google it's a better resource than should rank higher".

4.2 https://problogger.com/republishing-old-blog-posts/ said "If you’ve been blogging for a year or more, you might feel like you’re running out of ideas. There are plenty of great posts in your archive, but you’ve covered so many good topics already. How to Republish Old Blog Posts – and Why You’ll Want to".

4.3 From https://adage.com/article/industry-insights/why-you-need-update-your-old-blog-posts-and-4-tips-get-you-started/2165051, we can read the following " WHY YOU NEED TO UPDATE YOUR OLD BLOG POSTS (AND 4 TIPS TO GET YOU STARTED), " According to an Adobe study, 38% of users stop engaging with unattractive content. Imagine a reader landed on an old blog post of yours, and instead of being unimpressed and abandoning your website, they’d be met with updated content that accurately represents your expertise. Updating your old blog posts will breathe new life back into them. Not only will you be able to turn those posts into something you can be proud of today, but updating your old posts has a number of other benefits as well. By freshening up your content, you can boost your search engine optimization (SEO), increase your click-through rate, and possibly even see an increase in subscribers and customers.

Let's see what major SEO marketing players are saying about "update your old posts"

Updating old blog posts SEO from "How to update old blog posts for SEO"

1. Consolidate mid-performing content.

2. Add the current year to your heading tag.

3. Update meta tags for keywords with a low CTR.

4. Answer “people also ask” questions.

5. Improve your search intent match.

6. Add internal links to recent content.

7. Link to new research studies.

or How to republish old blog posts from How to Historically Optimize an Article: 6 Easy Steps to Follow

1. Run a Content Audit to Find the Posts That Fit Into One of the Buckets Above. ...

2. Edit the Article Copy. ...

3. Update the Title, But DON'T Change the URL. ...

4. Choose a More Relevant Call to Action. ...

5. Save Your Changes, Then Unpublish the Article. ...

6. Republish!

Neil Patel published an excellent article Bring Old Blog Posts Back to Life: 5 Strategies that Work

5. It is clear to you WHY, so run to your blog and UPDATE YOUR POST!!!!